Induction heater



Dec. 20, 1927. 1,653,014

E. ELKITTREDGE ET AL INDUCTION. HEATER Filed Auz. 10. 1926 2 Sheets-Sheet 1 i E J' 2 QPig-J.

INVENTOR.

ATTORNEYS.

Patented Dec. 20, 1927.

UNITED I STATES v 7 1,653,014 PATENT orr cs.

ERNEST E. KITTREDGE, JOSEPH A. FORSTER, AND RASMUS D. J'OHAN SEN, F ALAMEDA,

' CALIFORNIA.

INDUCTION HEATER.

Application filed August 10, 1926. Serial No. 128,872. 7

The present invention relates to improvements in induction heaters and has reference generally to those heaters in which the secondary coil of a transformer is made of tubular material so that water may be passed therethrough to be heated when a current is induced in the secondary coil. It is particularly proposed in this connection to provide a rigid bar connecting the'ends of the secondary coil and thereby completing the circuit and to utilize this bar so that the same becomes an integral portion of the entire de vice and performs an additional function besides that of shorting the secondary coil. It is further proposed to provide certain improvements in the structure of the core of a transformer by building only a section thereof of laminated material, while another section is made of solid material so that eddy currents may be produced in the latter section for heating the same while the water is guided directly through passages and the non-laminated section' It is furthenproposed to provide certain details of structure 1 departing from the methods now used, which will appear as the specification proceeds,

The preferred forms of our invention are illustrated in the accompanying drawings in which Figure 1 shows a side elevation of an instantaneous. heater embodying the gen eral principles of our invent-ion, Figure 2 shows in side elevation a tank heater illustrating substantially the same principles and Figure 3shows a fragmentary section taken along line 3-3 of Figure 2.

While we have shown only the preferred form of the invention we wish to have it understood that various changes or modifications may be made withinthe scope of the claims hereto attached without departing from the spirit of the invention.

in the form shown in Figure 1,, a copper bar 1 "of suitable length is bored from both ends as shown at 2 and 3 and is adapted for connection to the pipes 4: and 6 communicating with opposite ends of the two bores. The bar is solid in cross section at the central section thereof as shown at 7 so that the water passing through the pipes 4 and 6 cannot pass through the bar itself. The pipes 4 and 6 extend through opposite sections 8 and 9 of a transformer core, the two vertica'l legs 11 and 12 of which have the primary windings 13 encircling the same which letter counicate with the line wires 14:,

Coils 16 made of copper tubes encircle the two primary coils 13 and connect at opposite ends with the two bores 2 and 3. Each coil preferably consists of a plurality of tubes which may join the bores in the bar at different places as shown at 17 whereby an even flow is secured through all the tubes of the coil.

The manner in which this heater is used will be readily understood from the foregoing description. The pipe 4; is connected in any suitable manner to a source of water under pressure, such as a city water faucet, so that water runs therethrough and through the tube 16 into the tube 6 from where it is to discharged. When the switch in the line is closed a current passes through the primary coils 13 and a secondary current is induced in the secondary coils 16. The latter coils are heated thereby and this heat is directly transmitted to the water flowing therethrough so that the latter is heated at a minimum expense.

Tn the device illustrated in Figures 2 and 3, the core21 of the transformer is partly made of laminated material, as for instance in the legs 23, 24 and 26, and is partly made of solid material as in the leg 27. The two v legs 23 'and 26 have the primary coils 28 mounted thereon and the non-laminated leg 8 27 is perforated lengthwise as at 29 and connected through the pipes 31 and 32 with the tank or boiler 33. A coil 34 of conduct ing material of tubular cross section encircles the leg 27 and by-passes the perforations 29 so that a portion of the water flows through this coil Tn operation a current flowing through. the primary coils sets up eddy currents in the non-laminated'leg 27 of the core, whereby' heat is produced in the said leg which heat is transmitted immediately to the water flowing through the perforations 29. A portion of the water is by-passed through the tube 34 in which a secondary current is inma duced for heating the latter and the water passing through the same.

The relation of the heater to the tank or boiler 33 is readily understood and needs no explanation,

We claim 1.. An induction heater of the character described, comprising a core having primary windings thereon, a fluid conducting second ary coil encircling one leg thereof an elec= no trical conductor mounted parallel to the leg and having the ends of the coil secured there to and means for guiding Water into one end of the conductor and through the coil to the other end of the conductor.

2. An induction heater of the character described, comprising a conducting; bar be ing cored from either end, a fluid conducting coil of electrically conductive material connected, to the cores with the ends thereof so as to allow a liquid to run from one core through the coil to the other core and a primary coil supported Within the first coil for heating the latter when a current flows therethrough.

8., An induction heater of the character described, comprising a closed core having primary windings on opposite legs thereof a conducting; bar supported between the two legs, fluid conducting coils 0:? electrically conductive material surrounding the primary coils and connected to the bar so as to he shorted by the letter and means for passing a liquid through the said secondary coils.

4- In an induction heater of the character described., a core consisting partly of lami' nated and partly of non-laminated material, a primary coil encircling; the laminated section and means for passing a liquid to he heated through the non-laminated section,

5. An induction heater as defined in claim 4 in Which a secondary liquid conducting" coil encircles the non-laminated section and lay-passes a portion of the liquid.

In testimony whereof: We affix our signatures.

ERNEST E. KITTREDGE. JQSEPH A. FORSTER. BLASMUS D. JOHANSEN. 

